Take a simple ship, the BC Particle (mod)
http://forum.mongoosepublishing.com/viewtopic.php?p=900262#p900262.
BC Particle (mod), 110 kT, GCr 116
Particle spinal 7DD
499 Quad Pulse Laser turrets
400 PD Batteries
Meson Screen 250
Damper 250
Make the spinal a little smaller and squeeze in deflector shields:
BC Particle Deflector, 110 kT, GCr 116
Particle spinal 6DD
932 Quad Pulse Laser turrets
Meson Screen 50
Deflector 2000
Fight 10 BC Particle (mod) vs 10 BC Particle Deflector. Start at Long range.
BC Particle (mod)
Spinal: 2D +6[gunner] +5[software] +1[aid gunners] -2[range] -3[evade] -3[dodge] = +4, hit on 4+ (92%)
Average Damage: 7D * 1000 * 55% * 92% ≈ 12400
499 turrets: 2D +5[gunner] +3[software] +1[aid gunners] +1[accurate] +2[pulse] -2[range] -3[evade] = +7, Aver D 4,19
Average Damage: 499 * 4,19 ≈ 2090
Total damage: 10 * ( 12400 + 2090 ) ≈ 144900.
It takes 80666 hull + 28000 deflectors to kill an enemy ship.
144900 - 28000 - 80666 = 36234 damage on next enemy ship, 28000 of which is deflected, so it suffers 8234 damage
So totally
killing 11% of the enemy force each round.
BC Particle Deflector shoots back
Spinal: 2D +6[gunner] +5[software] +1[aid gunners] -2[range] -3[evade] -3[dodge] = +4, hit on 4+ (92%)
Average Damage: 6D * 1000 * 55% * 92% ≈ 11550
932 turrets: 2D +5[gunner] +3[software] +1[aid gunners] +1[accurate] +2[pulse] -2[range] -3[evade] = +7, Aver D 4,19
Average Damage: 932 * 4,19 ≈ 3900
Total damage: 10 * ( 11550 + 3900 ) ≈ 154500,
killing 19% of the enemy force each round.
Deflector ships wins easily.
Note that in a 1 vs 1 fight the deflector ship deflects all damage and wins without a scratch.